It is very important to prevent the vibration of a speaker system in a television receiver. Regarding a Cathode Ray Tube (CRT)-type television receiver, a problem has been reported in which the speaker vibration causes the vibration of a shadow mask in the CRT via a cabinet to consequently cause an image having a color shift, for example. Regarding a flat panel television receiver, for example, the liquid crystal or the plasma, the transmission of the vibration from the speaker easily causes the resonance sound of the cabinet or the resonance sound of the printed board. This gives a more strict specification regarding to small space and small clearance design, resulting in an obstacle against a design having a thinner thickness. Furthermore, the resonance sound by the vibration is also an obstacle for developing a television receiver having a higher sound quality. Therefore, it is important to establish an effective vibration damping mechanism in order to provide a speaker system having a wider bandwidth and a higher volume output.
Generally, a speaker retaining mechanism of a television receiver is structured so that a speaker is attached and fixed via a vibration damping member. For example, Japanese Patent Unexamined Publication No. 2000-138988 (Publication 1) discloses a technique to attach a vibration damping member to a retaining member of a speaker to thereby prevent vibration from being transmitted to a cabinet. Publication 1 discloses a technique in which to fix a vibration damping member to a speaker and to insert the vibration damping member to a boss of a cabinet or the like to fix the cabinet by a screw.
Japanese Patent Unexamined Publication No. 2000-103920 (Publication 2) discloses a technology to reduce the hardness of the vibration damping member and thereby improve the vibration damping effect.
However, when considering the vibration damping member disclosed in Publication 1 to be substituted with the vibration damping member having a reduced hardness disclosed in Publication 2, the stability of the speaker retention reduces as the hardness of the vibration damping member reduces, and this limits the reduction of the hardness. Specifically, regarding the configuration as disclosed in Publication 1, the hardness of the vibration damping member is limited to about 20 degrees, and when the hardness is 10 degrees or less, it cannot provide a stable retention of the speaker. Further, when a vibration damping member having a hardness of 10 degrees or less is used, it is even difficult to insert the vibration damping member to a boss. Therefore, the combination of techniques disclosed in Publications 1 and 2 is insufficient to provide a sufficient vibration damping effect.
The hardness such as 20 degrees or 10 degrees herein is represented by the rubber hardness based on JIS-K6253 (which is a standard defined by Japanese Industrial Standards (JIS) regarding the hardness test method for vulcanized rubber and thermoplastic rubber).
A vibration damping member having a low hardness also may cause an unstable speaker retention, due to a significant deformation of the vibration damping member itself, caused by the weight of the speaker. This gives a variation in the speaker position Thus, it is difficult to form a baffle face on the front face of the speaker completely, thus failing to provide reproduction having a stable sound quality.
Furthermore, recently, television receivers having structure in which the speaker is attached downwardly and a baffle is formed with a back cover are increasing. In such case, it is desired that the speaker is stably fixed after the assembling of the back cover.